I am brewing a milk stout for the first time on Sat. In my research on the style, I learned that in the past, milk stouts were promoted as healthy supplement to the diets of nursing mothers (due to the addition of lactose).
During Prohibition, malt syrups were sold as health tonics. Along with warnings about the dangers of diluting it 1:3 with warm water and allowing it to come in contact with yeast, then holding it at room temperature for a week.